Dust-tight blower



June 8, 1943. a. w. BREUER 2,321,126

' DUST TIGHT BLOWER I Filed April I5, 1941 3 Sheets-Sheet l arw June 1943- G. w. BREUEH;

DUST TIGHT BLOWER Filed April 3, 1941 3 Sheets-Sheet 2 JWQM/MJ- I 3' warlggg.

June 8, 1943. G. w. BREUER 2,321,126

DUST TIGHT BLOWER I Filed April 5, 1941 v s Sheets-Sheet s Patented June8, 1943 DUST-TIGHT BLOWER Grant William Brener, Chicago, Ill., assignor to Breuer Electric Mfg. 00.,

ration oi Illinois Chicago, Ill., a corpo- Application April 3, 1941, Serial No. 386376 1 Claim.

This invention relates to a combined blower and suction device of the portable type, and particularly to a hand portable device which is Q adapted and readily convertible for use as a blower, sprayer or vacuum cleaner.

It is an'object of this invention to provide an improved portable blower and suction device construction so as to provide a totally enclosed motor, commonly referred to as dust tight, for use in hazardous locations such asgrain handling and storage plants. Another object relates to an improved blower and suction device provided with a dust tight enclosed motor, and wherein means are provided for heat conduction and internal and external air circulation for cooling the motor and maintenance of its operating eiilciency.

Another object is to provide a blower device havinga dust tight enclosed motor; constructed so as to cause the stream of delivered air to first cool the motor and its parts and then to be I delivered in a. condition heated above the temperature of the surrounding atmosphere, to be useful in the dislodging of dust, dirt and moisture from motors, switch boards, and other electrical and mechanical equipment where dust, dirt and moisture, if allowed to remain might cause overheating, excessive friction, fire hazards, and the like.

Another object relates to an improved blower and suction device of the hand portable type hav ing an enclosed dust tight motor and a likewise commercially acceptable dust tight actuating switch mechanism so that no exposed potential sources of electrical sparks to a dust-laden atmosphere is present in the device.

Other objects relate to the economies of construction and the details and arrangement of parts which will be apparent from a consideration of the specification and drawings, wherein:

Fig. 1 is a side elevational view of my suction and blower device, largely in section.

Fig. 2 is a section on the line 2-2 of Fig. 1.

Fig. 3 is a plan view of the handle of my device.

Fig. 4 is a section on the line 4-4 of Fig. 2.

Fig. 5 is a section on the line 5--5 of Fig. 1.

Fig. 6 is a section on the line C- -U of Fig. 1.

Fig. '1 is a, section on the line I'-'I of Fig. .1.

Referring to the drawings, my combination suction and blower device comprises a high speed universal type driving motor having its armature Ill, field ll, commutator l2 and brushes i3 complely enclosed within a housing composed of the hood portion II and end closurev plate i5. By use ofthis type of motor I am enabled to provide through the carbon brush retaining portion 33 of an efllcient hand portable blower and suction cleaner as distinguished from usual dust tight constructions which employ the conventional type of slow speed motor which is heavierand not hand portable. The motor shaft I6 is journaled at one end in the bearing i'l seated in the domelike end portion ll of the hood ll, and at its.

other end in the bearing I9 seated in the plate I, 5 through which it extends. The plate I! is provided with an external elongated axial boss I, which aided by the felt sealing washers 9, prevents dust from traveling into the motor housing along the motor shaft.

A centrifugal fan 20, for the purpose of creating suction, or for delivering strong blast of air when the device is used as a blower or sprayer, is secured as at 2|, to the end of the motor shaft l6 which extends through the closure plate l5,the fan being enclosed by the fan casing 22 which is provided with the tangential exhaust port 23. The fan casing 22 is secured by suitable means, such as the screws 24 to the flange 25 of the outer body casing portion 26,"and is in communication therewith through the axial annular inlet 21. The outer body casing is preferably composed of two portions, so that in addition to the portion 26 I provide a, hood-like portion 28 having an annular seat 29 for engagement with the portion 28, the dome of the body portion 28 being provided with the axial inlet port 30. This outer body casing hood portion 28 is held in engagement' with the portion 26 and with the motor housing portion ll, by suitable means such as the screws 3| extending into the bosses 32, and in like manner may be conveniently disengaged for access to the motor brushes 'l3 which extend the motor housing ll. Likewise ready ability to remove the outer body casing hood portion 28 provides ready access for the purpose of removing accumulations of dust from the outer surface of the motor housing which may have been deposited from atmospheric dust drawn through the inlet port 30.

For the purpose of cooling the thus enclosed motor during operation of the device. I provide an internal air circulation by means o the blower fan secured to the motorshait I6. adcd by th annular baffle 35. As indicated by the arrows in Fig. 1, this fan 34 draws air from the area at the forward end of the motor en losure through the space between the armature Hi and field ll, whence it is guided by the baiile 35 to the center of the fan 3. The fan then throws the air outward through the space between the field ii and the motor enclosure H to the forward area of the enclosure, thus completing the internal air circuit which is continuous during the operation of the device. While making this circuit, the air absorbs heat from the carbon brushes I3, the commutator i2, armature Ill and field H, the heat being dissipated from the enclosed air to the metal of the motor enclosure.

To aid in this conduction of heat the motor enclosure I4 is provided with a plurality of internal longitudinally extending absorption fins II, thus providing a large and increasedsurface area to insure rapid heat absorption by the inner surface and conduction of heat to the outer surface of the housing I, the outer surface being provided with a plurality of heat radiation fins 31, these fins 31 being shaped and spaced in a manner whereby back pressure within the device is at a minimum. If desired, as indicated, the motor housing closure plate I! may also be provided with radial radiation fins I8 externally, and absorption fins 38 internally. The motor housing it and its cover plate It, and particularly all of the aforesaid absorption and radiation fins are preferably constructed of aluminum for rapid transfer of heat and lightness of weight.

In the operation of my device the fan 20 causes a large volume of air to be drawn in at a high velocity through the inlet port 30, and since the inlet port 30 is at an axial end of the casing opposed to the axial outlet therefrom which communicates with the fan casing 22, the stream of air is caused to pass between the external body casing and the sealing motor housing and to thereby washall portions of the motor housing and its external radiation fins to cause a rapid exchange of heat therewith, and which aided by the internal air circulation, previously described, cause a continuous and rapid cooling of the motor and its various parts. At the same time the air delivered through the fan outlet 23 is delivered at a temperature above atmospheric, or above that of the surrounding atmosphere for the purposes and attendant benefits previously set forth.

Fixedly secured to a convenient portion of the outer casing, such as to the portion 28 is a chambered handle 40 to provide a convenient grip for the operator. This handle houses a switch 4 I, in a manner whereby the operator can with the same hand by which the unit is held, regulate the starting and stopping of the drive motor. It will be understood that the illustrated type of switch I is largely diagrammatic and only indicative of many difierenttypes of switches which may be employed in like manner. It is, however, an additional object of this handle construction to house the switch H in such a manner as to be considered dust tight for safe operation in hazardous locations. For this purpose there is provided a reciprocating arm 42 which transfers sliding movement from the outer switch button 43 to the switch I by traveling through the internal handle chamber partition '44 which is of at least one-half inch in thickness and bored to close tolerance for passage of the arm 42, and thus provides the necessary safety factor for the operation of a make and break type of switch, such as the switch 4 l, in hazardous locations.

To additionally insure against the ingress of dust through the handle .40, the electrical conduit l8 enters it through the bushing 41 at close tolerances with about one-half inch or more of travel. Adjacent to this point of conduit entrance at the inside of the handle N there may be provided, although not illustrated, suitable means for eliminating strain on the conduit. so as to prevent possible disengagement thereof and to prevent short circuits, sparks, etc.

It will thus be seen that I have provided a dust-tight unit wherein all electrical parts are enclosed against the ingress of dust, including the driving motor and switch mechanism, so as to permit use thereof in hazardous locations, es-

pecially those having potentially explosive dusts.

For use as a suction cleaner a suction mouth nozzle may be conveniently attached to the inlet port 30 by means of the bayonet fixtures ll, or as in more common practice, there may be first attached a hose attaching means to which in turn a hose andsuction mouth is then attached. and a dirt bag may be secured to the fan chamber exhaust port 23 by means of the bayonet fixtures 49, For use as a sprayer or blower, suitable devices, conduits or nozzles may be secured to the exhaust port 23, air being drawn in through the port 30 and delivered in heated condition. It will be apparent, however, that whether my device be used as a suction cleaner or blower,

that due to its construction and major arrangement of parts, the centrifugal fan 20 has the combined function of cooling the enclosed dust tight motor and at the same time efllciently carrying out the blowing or suction creating function to permit the device to eiliciently operate as a portable blower, sprayer or suction cleaner, the fan being enclosed in a separate housing and providing directional flow and velocity to the air drawn in through the inlet orifice of the unit.

I claim as my invention:

A portable device of the class described adapted for use as a blower, sprayer or suction cleaning means, comprising a high speed universal type drive motor, a dust tight metallic enclosure for said motor in spaced relation to the stator thereof, a blower fan on the shaft of said motor within said enclosure and adjacent baflle means for directionally circulating air therein, a body casing surrounding said motor enclosure in spaced relation thereto, an axial inlet port at one end of said body casing, a fan casing at the opposed end of said body casing and in communication with an axial outlet opening thereat, a 7

tor shaft and a seat for its bearing, the said dust tight motor enclosure being further provided with radially projecting elongated carbon brush retention bosses, longitudinally extending ribs projecting from its inner surface to the motor stator, longitudinally extending ribs projecting from its outer surface to the body casing, and endwise outwardly projecting radially extending ribs on the dome end andcover plate thereof, said body casing being engaged to said motor enclosure and longitudinally slidably separable therefrom to permit access to the carbon brushes and their retainers and to permit removal of accumulated dust from the exterior portions of the motor enclosure.

GRANT WILLIAM BREUER. 

